January 2007 marks the start of the fourth year on Mars for NASA's Spirit and Opportunity rovers. The two hardy explorers, along with several orbiting spacecraft, are capturing unique views that help us learn more about our planetary neighbor. With the next mission scheduled to launch in August 2007, the red planet is indeed ready for its closeup.

At left, NASA's Mars rover Opportunity reached "Victoria Crater" in October 2006. The crater provides a whole new vista to explore in 2007

Layers of ice-rich deposits near the north pole can be seen in this this false-color view. Observed variations in the layers' thickness and composition will yield information about recent climate cycles on the red planet.

Diverse Terrain

Diverse materials and formations are evident is this color-enhanced view from Mars Reconnaissance Orbiter.

The bright material may be rich in clays and date back to a time when Mars had a wetter environment.

Roaring Jets

Jets of carbon dioxide gas erupting from the south polar ice cap are depicted in this artist's concept. Researchers, interpreting new observations by NASA's Mars Odyssey orbiter, think the jets erupt with the approaching spring.

This interpretation reveals that this part of the planet is more dynamic than expected

Underground Ice

The upper image is a radargram from the European Space Agency's Mars Express orbiter. It shows layered deposits underneath the surface near the north pole. The data suggests that the material between the two whitish lines, or radar traces, is nearly pure water ice. The lower image shows the position on the ground where the spacecraft passed overhead.

Mars Express arrived at Mars in December 2003. Its radar instrument is jointly funded by NASA and the Italian Space Agency.

Next Mars Mission

The Phoenix Mission, scheduled to launch in August 2007, will land on icy soils near the north polar ice cap and study the history of the water in these soils and any associated rocks. The lander will also monitor the polar climate.

The lander is NASA's first to investigate an icy region on Mars. It will search there for carbon-bearing compounds, potential building blocks of life.